Evacuation assistants are expected to spread the escape route information and lead evacuees toward the exit as quickly as possible. Their leading behavior influences the evacuees＇ movement directly, which is confirme...Evacuation assistants are expected to spread the escape route information and lead evacuees toward the exit as quickly as possible. Their leading behavior influences the evacuees＇ movement directly, which is confirmed to be a decisive factor of the evacuation efficiency. The transmission process of escape information and its function on the evacuees＇ movement are accurately presented by the proposed extended dynamic communication field model. For evacuation assistants and eevacuees, their sensitivity parameter of static floor field（SFF）, kL S, and kS, are fully discussed. The simulation results e indicate that the appropriate kL Sis associated with the maximum kSof evacuees. The optimal combinations of kL Sand e kSwere found to reach the highest evacuation efficiency. There also exists an optimal value for evacuation assistants＇ information transmission radius.展开更多
A finite-different time-domain （FDTD） algorithm is applied in this paper to study the bistatic electromagnetic（EM） scattering by a conductive cylinder covered with inhomogeneous, collision, cold, time-varying plas...A finite-different time-domain （FDTD） algorithm is applied in this paper to study the bistatic electromagnetic（EM） scattering by a conductive cylinder covered with inhomogeneous, collision, cold, time-varying plasma. The collision frequency of plasma is a function of the electron density and the pressure of the background gas. The plasma density follows any prescribed distribution function of the rise time of plasma and the radius of the column. The bistatic radar cross section （RCS） of the conductive cylinder covered with inhomogeneous time-varying plasma and inhomogeneous steady-state plasma is calculated under different conditions. The results illustrate that a plasma cloaking system can successfully reduce the RCS of the conductive cylinder.展开更多
The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products,as well as a fundamental space for mine monitoring,surveillance,communications and c...The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products,as well as a fundamental space for mine monitoring,surveillance,communications and control systems.An investigation of electromagnetic interference in coal mines is essential for the enhancement of performances of these systems.In this study,a new field method is provided in which radiated emission tests in coal mine laneways have been carried out.We conclude that:1) the wiring motor vehicles can radiate interference with a bandwidth up to 1 GHz and with an amplitude 10 dBμV/m higher than the background noise;2) the PHS(Personal Handy phone System) mobile communication system can cause interference 40 dBμV/m higher than the background noise;3) an interference 25 dBμV/m higher than the background noise can be generated during the communication at a working bandwidth of 48.8 MHz;and 4) power cables,battery vehicles as well as mechanical and electrical dong rooms have little effect on the electromagnetic radiation environment in coal mine tunnels.展开更多
In this paper, based on the characteristics of polar codes, a new decode-and-forward strategy called generalized partial information relaying protocol is proposed for degraded multiple-relay networks with orthogonal r...In this paper, based on the characteristics of polar codes, a new decode-and-forward strategy called generalized partial information relaying protocol is proposed for degraded multiple-relay networks with orthogonal receiver components(MRNORCs). In such a protocol, with the help of partial information from previous nodes, each relay node tries to recover the received source message and re-encodes part of the decoded message for transmission to satisfy the decoding requirements for the following relay node or the destination node. In order to construct practical polar codes, the nested structures are developed based on this protocol and the information sets corresponding to the partial messages forwarded are also calculated. The proposed scheme is proved to be capable of achieving the theoretical capacity of the degraded MRN-ORCs while still retains the low-complexity feature of polar codes. We perform simulations to testify the practicability of the proposed scheme and compare polar codes by using successive-cancellation list decoder(SCLD) with traditional low-density parity-check(LDPC) codes. The results show that the obtained polar codes provide significant gain.展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2011CB706900)the National Natural Science Foundation of China(Grant Nos.71225007 and 71203006)+2 种基金the National Key Technology Research and Development Program of the Ministry of Science and Technology of China(Grant No.2012BAK13B06)the Humanities and Social Sciences Project of the Ministry of Education of China(Grant Nos.10YJA630221 and 12YJCZH023)the Beijing Philosophy and Social Sciences Planning Project of the Twelfth Five-Year Plan,China(Grant Nos.12JGC090 and 12JGC098)
文摘Evacuation assistants are expected to spread the escape route information and lead evacuees toward the exit as quickly as possible. Their leading behavior influences the evacuees＇ movement directly, which is confirmed to be a decisive factor of the evacuation efficiency. The transmission process of escape information and its function on the evacuees＇ movement are accurately presented by the proposed extended dynamic communication field model. For evacuation assistants and eevacuees, their sensitivity parameter of static floor field（SFF）, kL S, and kS, are fully discussed. The simulation results e indicate that the appropriate kL Sis associated with the maximum kSof evacuees. The optimal combinations of kL Sand e kSwere found to reach the highest evacuation efficiency. There also exists an optimal value for evacuation assistants＇ information transmission radius.
基金supported by National Natural Science Foundation of China (No. 60471002)the Natural Science Foundation of Jiangxi Province (No. 0412014)
文摘A finite-different time-domain （FDTD） algorithm is applied in this paper to study the bistatic electromagnetic（EM） scattering by a conductive cylinder covered with inhomogeneous, collision, cold, time-varying plasma. The collision frequency of plasma is a function of the electron density and the pressure of the background gas. The plasma density follows any prescribed distribution function of the rise time of plasma and the radius of the column. The bistatic radar cross section （RCS） of the conductive cylinder covered with inhomogeneous time-varying plasma and inhomogeneous steady-state plasma is calculated under different conditions. The results illustrate that a plasma cloaking system can successfully reduce the RCS of the conductive cylinder.
基金supported by the National Natural Science Foundation of China (No.50674093)the National Scientific and Technological Support Projects (No.2006BAK03B00) and the Pingdingshan Coal Mine Group
文摘The electromagnetic environment of laneways in underground coal mines is an important area for the design of new electronic products,as well as a fundamental space for mine monitoring,surveillance,communications and control systems.An investigation of electromagnetic interference in coal mines is essential for the enhancement of performances of these systems.In this study,a new field method is provided in which radiated emission tests in coal mine laneways have been carried out.We conclude that:1) the wiring motor vehicles can radiate interference with a bandwidth up to 1 GHz and with an amplitude 10 dBμV/m higher than the background noise;2) the PHS(Personal Handy phone System) mobile communication system can cause interference 40 dBμV/m higher than the background noise;3) an interference 25 dBμV/m higher than the background noise can be generated during the communication at a working bandwidth of 48.8 MHz;and 4) power cables,battery vehicles as well as mechanical and electrical dong rooms have little effect on the electromagnetic radiation environment in coal mine tunnels.
基金supported by the National Natural Science Foundation of China (No.41574137, 41304117)
文摘In this paper, based on the characteristics of polar codes, a new decode-and-forward strategy called generalized partial information relaying protocol is proposed for degraded multiple-relay networks with orthogonal receiver components(MRNORCs). In such a protocol, with the help of partial information from previous nodes, each relay node tries to recover the received source message and re-encodes part of the decoded message for transmission to satisfy the decoding requirements for the following relay node or the destination node. In order to construct practical polar codes, the nested structures are developed based on this protocol and the information sets corresponding to the partial messages forwarded are also calculated. The proposed scheme is proved to be capable of achieving the theoretical capacity of the degraded MRN-ORCs while still retains the low-complexity feature of polar codes. We perform simulations to testify the practicability of the proposed scheme and compare polar codes by using successive-cancellation list decoder(SCLD) with traditional low-density parity-check(LDPC) codes. The results show that the obtained polar codes provide significant gain.
